Internal combustion engine



Sept. 27, 1932. w. H. ROBERTSON INTERNAL COMUSTION ENGINE .1| 3 original Filed Dec. 13, 1919 Sept. 27, 1932.

W. H. ROBERTSON INTERNAL CMBUSTION ENGINE iginal Filed Dec. 13, 1919 4 Sheets-Sheet 2 /VVENTOR l/f//f'am H /Paer'son A TTU NEY 4 sheets-sheetv 3 INVENTo/e 7 f 7 O .5 1 I v ..,l m 1 E 1 .d wweo /wo f w@ Sept. 27, 1932. w. H. ROBERTSON 'INTERNAL coMBUsTIoN ENGINE origia1 Filed Dec. 1:5, 1919' W. H. ROBERTSON INTERNAL COMBUSTION ENGINE Sept. 27, 1932.

Original Filed Deo. 13, 1919 4 Sheets-Sheet 4 Patented Sept. 27, `1932y WILLIAM ROIBERTSON, OF DAYTON, OHIO INTERNAL COMBUSTION ENGINE PATENT OFFICE Qriginal application led December 13, 1919, Serial No. 344,715; Divided and this application led .Tune

, 14, 1928. Serial No. 285,414.'

rllhis invention 'relates to internal combustion engines, and more especially to two cycle engines of the Diesel type.

One aim of the invention is to provide an vengine having the highest possible thermal eiicieney, and, in carrying out .this aim, novel means are provided for securing an intimate mixture of the air for supporting combustion and the fuel separately injected' lointo the cylinder; novel means are provided for scavenging the. engine in the most effective manner; and novel means are provided for utilizing the energy of the exhaust gas.

I aim to secure high thermal efficiency by providing that the air used to supportY conibustion shall be initially compressed by the operation of the engine and that it shall be caused to swirl through the engine cylinder in order more thoroughly to mix with the 2o injected fuel. The air which enters the cylinder after the explosion has taken place is likewise caused to rotate as it passes through the cylinder so that, by its swirling action, this air will Veectively scavenge the cylinder.

fiywheels. By making the moving parts of equal weight, the vibration `which one set of parts would tend to set up is offset by the equal and opposite ei'fect of the other set of parts which operates contrarywise.

A further-object is to reduce to a minimum 5 the weight of the engine per horsepower.

This object is accomplished in one manner by utilizing flywheels of comparatively small mass and gearing them up to the engine crank shafts so that the flywheel elements,

5c by their increased speed, will be effective to produce a steady flow of power from the enffine.

o In this connection it is a further. object that the moving element of the engine operated air compressor shall act as one iiywheel element, and that the turbine rotor shall act as the other iywheel element, thereby reducing the number of parts as well as the weight per horsepower.

Another object of the invention is to providenovel means for injecting fuel into the engine in such a manner as to be thoroughly mixed with the combustion air lcharge to insure a uniform fuel mixture.

A vfurther object is to provide a valveless fuel pump for injecting fuel into the engine.

A further object is to provide for the control of the engine speed by controlling the operation of the pump by the engine through manual means. One manner of accomplishingthis object is to 'control the amount of fuel-forced into the engine cylinder during each cycle of the engine. operation.

Afurther 4object is to eliminate noise by providing a mumer of improved construction which will relieve the exhaust of a large portion of its energy while permitting a rapid escape into the outside atmosphere. In carrying out this object Iprovide that the exhaust turbine shall act also as the muiiier. In accomplishing this object, the

number of engine parts and the weight perv horsepower are reduced.

Other and further objectsand,advantages Vof the present invention will be apparent from the following description of a preferred 'embodiment thereof,`reference being made to.

the accompanying drawings.

In the drawings:

F ig. l is a side elevation of an engine embodying the presentl invention;

Fig. 2 is a sectional View taken on line 2 2 ofI Fig. l; i

Fig. 3, Fig. 4 and 5 are sectional views taken on line 3-3 of Fig. 2 showing the engine parts in their relative positions during diderent stages of the engine cycle;

Rus-sun) to deliver a relatively large amount of fuel Y per engine cycle;

Fig. 12, Fig. 13, Fig. 14 and Fig. 15 are sectional views similar to those shown in Fig. 7, Fig. 9, Fig.10 and Fig. 11 showing stages of pump operation when the pump is set to .deliver a relatively small quantity of fuel per engine cycle;

Fig. 16 is a sectional view taken on line 16-16 ofFig. 2;

Fig. 17 is a sectional view taken on line Y 17-17 of Fig. 2;

nozzle; and Fig. 21 is a sectional view taken on line 4 21-21 of Fig. 20.

Fig. 18 is a sectional view taken on line 18--18 of Fig. 1;

Fig. 19 is a sectional view taken on line 19-19 of Fig. 1;

Fig. 20 is an end elevation of the fuel Referring to the drawings, a base 30 supports crank cases 31 and 32, which support between them a cylinder 33 in which slide pistons'34 and 35. Piston 34 is connected by rod 36 with crank 37 formed preferably integrally with crank shaft 38. Piston 35 is corinected by--rod 39 with crank 40 also formed integrally with crank shaft 41.

Shaft 38 directly drives gear 42, fuel pump cam 43, and planetary gear arm 44; while turbine rotor 45 is mounted to rotate there upon.

. Shaft 41 directly drives gear 46, slide valve` cams 47,48, and planetary gear arm 49, while fan rotor 50 is mounted to rotate thereupon.

A turbine housing 51 mounted upon crank case 31 is divided by a partition 52 into a turbine gear case 53 and al turbine rotor case 54. The end wall of housing 51 is provided with apertures 55 and with. inwardly rojecting ledges 56 and 57 see Fig. 16; an the cylindrical wall of housing 51 is provided with internal gear 58, which meshes with planetary gears 59 and 60, rotatably mounted on gear arm 44. Housing 51 is provided with holes 55a, see Fig. 16. Gears 59 and 60 mesh with pinion 61 attached to bearing sleeve 62 which supports turbine rotor 45 which vrotates normally i'n'the direction of arrow 45a.

Rotor 45 is provided with blades 63 ar- 'ranged to be impinged upon by the exhaust gases which enter through exhaust pipe 64 and circulate through the rotor 45 and into rotor case 54 as indicated approximately by arrows 65. The ledge 56 divides the spent gases into two streams which tend to meet Fig. 10 and Fig. 11 are sectional against the ledge 57, this ledge 57 serving to the rotor blades may escape through openings 55a.

Exhaust pipe 64 is connected with annular exhaust passage of cylinder 33, and passage 70 is connected with cylinder 33 through exhaust ports 71.`

A fan housing is provided with a fan rotor case 81 provided with a central aperture 82 communicating with fan gear case 83, which in turn is connected with the interior of crank case 32 through holes'84. Housing 80 is provided with an internal gear 85, see Fig. 2 and Fig. 17, whichY meshes with planetary gears 86 and 87, rotatably mounted upon gear arm 49. Gears 86 and 87 meshwith pinion 88 which is directly connected with fan rotor 50. The normal direction of rotation of the gearing is indicated in Fig. 17 by arrows 49a, 86a and 88a.

Fan casing 81 is connected by air intake pipe 90 with annular intake chamber ,91, see

'Figs 2 and 19. Communication between chamber 91 and cylinder 33 is controlled by slide valve 92, provided with ports 93.

Crank case 32 supports a rod 94, see Fig. 3, which supports bell crank levers 95, 96 carrying cam rollers 97, 98 respectively, cooperating with races provided with cams 47, 48 respectively. Rollers 97 98 are connected with arms 99, 100 respectively of the valve 92. Levers 95, 96 cooperate with counterbalance levers 101, 102 respectively, mounted upon rod 103 carried by crank case 32.

' Crank cases 31 and 32 are provided with airl inlet ports 111 and 112, respectively, closed by spring pressed valves 113 and 114, respectively, which are arranged to be opened by suction within the crank cases during the compression stroke of the pistons. (Jrank cases 31 and 32 are connected by pipe 115.

Referring to Figs. 6' to 8 inclusive, the fuel pump will next be described. Pump-cam 43 is provided with races 120 and 121, cooperating with rollers 122 and 123, respectively, carried by levers 124 and 125 respectively. Levers 124 and 125`are connected by studs 126 and 127, respectively, with plungers 128 and 129, respectively, which slide within sleeve y y 144 and 145, respectively, through which pass studs 146 and 147, respectively, carried by fulcrum plate 148. Plate 148 is provided with a slot 149 through which projects a stud 150 mounted upon a wall of crank case 31. A spacing washer 151 is located between crank case 31 and-plate 148 to maintain plate 148 in proper alignment.

As lever 125 must cooperate with elements located on opposite sides of cam 43, said lever 125 is composed of section 1250i carrying the cam roller 123, section 125e attached to plunger 129, and an intermediate connecting section 1257). f

Plate 148 carries a block 152 to which is attached by means of stud 153 a bell-crank lever 154 which is rotatably supported upon the base 30. f

The cycle of operations of the pump is shown. by Figs. 7, 9, 10 and 11. In Fig. 7, the plungers 128 and 129 are located in touching relation opposite the fuel inlet port 134. Turning cam 43 in the direction of the arrow 155 causes the plungers first to be separated, as shown in Fig. 9, causing fuel to be sucked I into sleeve 130. Further turning of canr43 171 respectively, carried by shaft 172 which is causes plungers 128 and 129 to move equal distances to the respective positions shown in Fig. 10 which are opposite outlet port 137. Further turning of cam 43 causes plungers 128 and 129 to come together `as shown in Fig. 11, thereby causing the fuel to be forced out through pipe 136. When a revolution of cam 43 has been completed the pump plungers will be returned to the respective positions shown in Fig. 7. The pump cam 43 is timed so thatfuel will begin to be ejected through pipe 136 at the end of the compres'- sion stroke.

The speed of the engine is controlled by moving lever 154 so as to raise or lower the fulcrum studs 146 and 147. 'If studs 146 and 147 be moved to the upper-most position much less fuel will be pumped from the fuel tank and ejected'into pipe 136. With the fulcrum studs in such a position, the operation will be as illustrated in Figs. 12,13, 14 and 15 showiner positions of the plungers correspondingto igs. 7, 9, 10 and 11 respectively. It will .3 be observed in Fig; 13 that the plungers are The fuel nozzle designated as a whole by numeral 160 will now be described. Nozzlee 160 comprises casting 161 extending through the cylinder wall and provided with a passage 162 connected with pipe 136. Passage 162 lleads into passage 163 arranged axially of cylinder 33; and in passage 163 is loosely journalled a shaft 164, provided at each end with a perforated disc 165. 7

Gears 42 and 46 mesh with gears 170 and rotatably mounted upon frame 30 and care ries a driving pulley 173. Pulley 173 may be provided with a crank 174 for starting the engine.

The operation of the engine is .as follows: f'

Air for combustion and scavengingpurposes is drawn during thel suction stroke, throughports 111 and 112 into the crank cases 31 and 32. During the operation of the engine, the fan 50 draws air in through passages 84-and blows it out through air intake pipe 9,0 and into annular passage 91 where it is initially compressed. This air enters the cylinder 33 at a time to be described later and is caused to swirl by reason of the tangentialvr At high speed, however, these valves are constantlyl open because the fan blower attains sufficient speed to compress the air before it enters the cylinder. Therefore, at this highV speed the blower furnishes a? greater volume of air to the cylinder than that furnished, merely by the displacement of the pistons.4 Hence, the partial vacuum which it creates due to sucking air through the crank cases faster than the pistons could pump it,

would create a sufficient vacuum to -keep the valve ports 111, 112 open constantly.

At the end of the compression stroke fuel is ejected through nozzle 160 and spreads outover the surfaces of the discs 165 and fills 'the perforations. The swirling air as it passes through the perforated discs picks up the fuel drops and causes them to be whirled around together with the fuel mist which is thrown off the edges of the rotating discs. In thisv manner an intimate vmixture of fuel and combustion air is rap-idly secured. i

The fuel is preferably ignited by the heat of compression, although the well known forms of electrical ignition may be usedat the start. The combustion space is preferably onetwelfth the displacement space so that the air will be raised to a temperature sufficient for fuel ignition purposes by compressing it within the cylinder.

During a portion of the combustion stroke the fuelcontinues to burn, and to develop power for-driving the pistons. The fuel pump is operated so that the maximum amount of fuel injected is s ucient to con.- sume substantially all of the combustion air when the engine operates at full load. The engine speed is decreased by adjusting the lever 154 so that less fuel will be injected.

As the pistons 34 and 35 are driven outexhaust ports 71 will be uncovered before the piston 35 uncovers ports 93. The swirling products of combustion will pass out ports 71 into passage 7 0 in the manner indicated by arrows 71a in Fig. 18. The exhaust will begin tov expand as it passes through pipe 64 to the turbine chamber 54 and will .attain a` velocity sufficient to drive the turbine rotor 45. Some of the energy of the exhaust will be given up to the rotor to assist in driving the engine. The passing'of the exhaust through the rotor and the dividing of it by ledge 56 into two streams which meet against the ledgey 57 is effective in preventing the sudden rush of the exhaust into the atmosphere.

By the time piston 34 has moved to outer dead-center position (see Fig. 4),piston 35 willhave completely uncovered ports 93 in valve 92, permitting the initially compressed air in the chamber 91 to rush in and blow out the dead air at the end of the cylinder where nearest piston 35.

As the rotation of shafts 38 and 41 continues in the direction of arrows 38a and 41a, respectively, the pistons 34 and 35 move in direction of arrows 34?) and 35?) respectively. While exhaust ports 71 are being covered by the piston 34, valve 92 is being moved to open position by cams 47 and 48, so that by the time ports 71 are fully covered, valve 92 is in full open position as shown in Fig. 5. Before ports 71 are closed, `fresh air, which has been initially compressed by the outward movement of the .pistons or the centrifugal blower depending onthe speed of the motor, will swirl through the cylinderand completely drive out the exhaust. This fresh air by its whirling motion tends to maintain its own plane of rotation, and, therefore, the mixing of the fresh air with the dead air will be reduced to a minimum.

After ports 71 are closed, the slide valve 92 remains open, permitting additional fresh air to pile up whatever pressure the blower may generate. l i

In an ordinary two-cycle engine the intake port would have been opened sooner than in the present invention, thereby allowing less time for the pressure of the exhaust to drop low enough for fresh air to enter. In an ordinary two-cycle engine, the intake port would also have been closed before the exhaust port closed, thereby allowing less time for fresh air to enter to drive out the exhaust, than is the case of the present invention. Therefore, the present invention is adapted to be operated at a much higher speed than the ordinary two-cycle engine.

A further advantage 'of the present invention over the ordinarytwo-cycle engine ,is thatl the pistons displace a volume of air in the crankcases equal to a very large percent of the totalY crank case and cylinder volume. The result is that the pistons themselves raise the pressure of the air higher it reached by the time piston 35 has reached inner dead-center position.

When the pistons 34 and 35 have reached the inner dead-center positions shown in Fig. 2, fuel is again injected and burned, and the cycle of operations which has been described is repeated.

During the burning of the fuel the mixing of the Iburnt air with fresh air is reduced to a. minimum in the present invention. The fresh air is caused to whirl as it enters the cylinder by means hereinbefore described. As this air is compressed it is still whirling and the vfuel nozzle discs 165 take up this motion. By the time the pistons reach the inner dead-center the air is stil] whirling though retarded by the fuel nozzle stem and by friction of the air itself.

However, the discs 165 have stored some energy during the first part of the compression stroke and give up this energy to the air during the latter part of the compression stroke tending to maintain the whirling motion. With the pistons located at inner deadcenter, most of the compressed airis confined between the discs 165. As the pistons 34 and 3.5 separate, the air expands through and around the discs carrying the fuel oil with it, which burns as itis ejected from the nozzle and mixes with the air. Timing of the How of fuel being regulated by the movement of the fuel pistons 128 and 129, operated by the cam 43 so that the How'of fuel at any instant corresponds to the flow of air passing through the discs as the engine pistons 34 and 35 separate. The proper, ratio between the iow of fuel and the How of air past the discs is obtained by reason of the design of the cam 43. It is guite evident that by -this method of having a proper ratio between the flow of fuel and the flow of air past the ignition point that a complete and continuous combustion can be obtained at all speeds of the engine. The air supporting combustion has still enough whirling motion to maintain itself in its own plane of rotation, and, therefore, the burnt air does not tend to mix with the fresh air which ispushing outwardly from the center point ofthe cylinder toward the outer ends thereof.

Vibration is substantially eliminated by providing in the one cylinder, two pistons of equal weight which drive two crank shafts in opposite directions through connect-ingl .balances 101 and 102 are provided.

By eliminating vibration, the extent of use of the engine is greatly increased. It can be operated without a heavy foundation and therefore may be readily transported while in operation. It can therefore be constructed as a portable power device for all sorts of that one may act as a high-speed fan rotor,

purposes, including domestic use and use as the prime mover of a portable hand tool such as a drill, saw or planer.

The portability of the engine is further increased by the use of small flywheels which are geared up to the crank shafts so as to develop the same energy of rotation as the conventional large flywheel directly connected to the crank shaft. l

The gearing up of the fiywheels is taken advantage of by constructing the flywheels so and the other may serve as a turbine rotor converting some of the energy of the exhaust into useful power, and, at the same time, serving as one element of an exhaust muiier.

It is to be understood that the invention is not restricted to the particular impulse turbine disclosed, but that other types such as the conventional De Laval type may be used. In such a case the exhaust would enter on one side of the turbine rotor and leave on the opposite side, and would then pass into muffier passages in the turbine case and then out into the atmosphere.

It is to be understood that some form of cooling system is used for cooling the cylinder and fuel nozzle. For sake of clearness, the cooling system has been omitted from the drawings. j

While the form of mechanism herein shown and described constitutes a preferred form of embodiment of the invention, it is to be understood that other forms might bc adopted, all coming within the scope ofthe claims which follow. l

The present application is a divisional application of my former application led on the 13th day of December, 1919, Ser. No.

causing the pistons to be moved in constant l spaced relation to positions adjacent the 011tlet port whereby to closer olf the inlet port and to open the outlet port, then causing the pistons to be moved together adjacent the outlet port, and then to` be moved in constant relation until the inner lends thereof are again adjacent the inlet port.

2. In an internal combustion engine, the combination with a cylinder and a piston reciprocating therein; of a lcrank shaft connected with the piston; a fuel pump comprising a cylinder having inlet and outlet ports, a pair of pistons reciprocating in said cylinder, and mechanism positively connecting each piston with the crank shaft, said mechanism causing the inner ends of the pistons to be separated adjacent the inlet port, then causing the pistons to be moved in constant spaced relation to positions adjacent the outlet port whereby to close off the inlet port and to open the outlet port in timed relation with the translatory movement of the engine piston, then causing the pistons to be moved together adjacent the outlet port, and then to be moved in constant relation4 until the inner ends thereof are again adjacent the inlet port; and means for adjusting the mechanism to vary the separation of the pistons.

3. In. an internalfcombustion engine, the combination with a cylinder and a piston reciprocating therein; of a crank shaft connected with the piston; a `fuel pump comprising a cylinder having inlet and outlet ports, a pair of pistonsreciprocating in said cylinder, and mechanism positively connecting each piston with the crank shaft, for causing the pistons to recede to uncover t-he inlet port and to suck in fuel for causing the pistons to transfer said fuel from the inlet port to the outlet port and thereby closing off the inlet port and opening the exhaust port, for causing the pistons to squeeze the fuelout through the exhaust port.

v 4.'In an internal combustion engine, the combination with a cylinder and a piston reciprocating therein; of a crank shaft connected with the piston; a fuel pump comprising a cylinder having inlet and outlet ports, a pair of pistons reciprocating in said cylinder, and mechanism positively connecting each piston with the crank shaft,for causing the pistons to recede to uncover the inlet port and to suck in fuel for causing the pistons to transfer said fuel from the inlet'port to the outlet port and thereby closing olf the inlet port and opening the exhaust port, for causing the pistons to squeeze the fuel out through theexhaust port, and means for adjusting said mechanism to adjust the receding movement of the pistons whereby to vary the quantity of fuel injected into the engine cylinder.

5. In anV internal combustion engine, the combination with a cylinder and a piston reciprocating therein; of a fuel injector pump connected therewith having a pair of pistons pressed air and misting thereof Within a portion of the space occupied by the compressed air, combustion of said fuel inist in its said air at the end of the compression and continuing simultaneously with the introduction of fuel during the expansion of the products of combustion. A

7. A process of combustion and thermodynamic conversion within an engine comprising the confinement within a limited I space of a gaseous working medium consisting substantially entirely of unburnt air,

` compression of said confined air by reduction of 'volume of the space wherein it is confined, the gradual introduction of a liquid fuel at a point in the space occupied by the confined air, mist-ing of the fuel at the end of the compression and while being introduced in the space occupied by the confined air, combustion of said fuel mist as the confined air passes the zone of misting of said fuel during-the expansion of the products of combustion.

8. In an internal combustion engine, the combination with a cylinder having a combustion zone at the head thereof and a piston reciprocating therein for compressing air substantially entirely rearward of said combustion zone; of a fuel injector pumpconnected therewith having a pair of pistons reciprocating in the pump cylinder; and means cooperating with said engine for controlling the rate of movement of said pump pistons in proportion to the rate of movement of said engine pistons, said means being adapted for manual adjust-ment to vary the amount of fuel injected.

, 9. In an internal combustion engine, the combination with a cylinder having a combustion zone at the head thereof and a piston reciprocating therein for compressing air substantially entirely rearwardly of said zone; of a fuel injector pump connected therewith for positively controlling the rate of injection of fuel Within said cylinder in 'accordance with the rate of air flow past said Zone during expansion.

10. In an internal combustion engine, the" tons reciprocating in a pump cylinder; mechanism positively connecting each piston to the engine; and means cooperating with said engine for positively controlling the rate of movement of said pump pistons in proporing substantially entirely of unburnt air,

compression of said confined air reducing the volume, the introduction of liquid fuel into the compressed air at a zone of combustion at a rate such that the flow of fuel entering is approximately proportional to the rate of air flow past said zone during expansion.

In testimony whereof I affix my signature.

WILLIAM I-I. ROBERTSON. 

